66211257 has 64 divisors (see below), whose sum is σ = 112803840. Its totient is φ = 33696000.

The previous prime is 66211253. The next prime is 66211259. The reversal of 66211257 is 75211266.

It is not a de Polignac number, because 66211257 - 2² = 66211253 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66211253) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 655507 + ... + 655607.

It is an arithmetic number, because the mean of its divisors is an integer number (1762560).

Almost surely, 2^66211257 is an apocalyptic number.

It is an amenable number.

66211257 is a deficient number, since it is larger than the sum of its proper divisors (46592583).

66211257 is a wasteful number, since it uses less digits than its factorization.

66211257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214.

The product of its digits is 5040, while the sum is 30.

The square root of 66211257 is about 8137.0299864263. The cubic root of 66211257 is about 404.5547247680.

Subtracting 66211257 from its reverse (75211266), we obtain a palindrome (9000009).

The spelling of 66211257 in words is "sixty-six million, two hundred eleven thousand, two hundred fifty-seven".